I am posting this for my friend, the earpiece speaker stopped working on his Pre, and the only way he can use the phone now is by using the speaker phone. I faintly remember someone posting a similar problem and solution to this, but after doing a search on here and on google, I couldn't find anything about it.

Can someone who had that problem please post the procedure on how to resolve this? I think I remember it having something to do with using Pandora, and the phone thinking that the head phones are still plugged in or something like that.

Plug in some headphones. Open up Padora or the music app. Play some music.
Then stop the music. Close the app & wait about 5-10 seconds. Remove the headphones.

^ this ^

pretty common issue. especially if you use pandora.

also hot days and sweaty faces can get sweat into the cracks of an earpiece and fry something. pretty hard to fry a speaker but it can still fry the board. just thought i'd mention that too.. since most people dont pay attention.. and i've seen it alot - in other phones